Thermoforming process is a vacuum forming process in which heated thermoplastic sheets are molded by using pressure vacuums to suck the sheet against a mold. This process uses larger air pressure differences and male core plugs. The process is used to manufacture various types of plastic items such as point of sale display trays, food processing trays for microwaves, meat handling, containers for deep freezing, tubs used to store margarine, ice cream, delicatessens, packaging used for snacks, bakery products, sandwich bags, beverage drinking cups, and blister packaging, etc. The process is also used for the packaging of pharmaceuticals items, toiletries products, and electronic items, etc. Thermoforming is often used to produce many types of products that used to be made by materials such as wood, metal, glass and paper.
Thermoforming is a quick, very efficient and low cost manufacturing process that is also being used for large jobs such as panels and siding for houses and other structures. Thermoforming is ideal for items that only have one visible side, such as food container, as one side can be formed with various specifications and detail, and the other side can remain unformed.
There are different types of molds that can be used in thermoforming, including machined aluminum molds, cast aluminum molds and composite molds. Thermoforming can be done with different types of thermoplastics such as PVC, polypropylene, polystyrene, Cpet, EVOH, and Apet etc. These materials are non-toxic and they do not allow odors and moisture to pass through them easily, so they are often used in the food processing industry.
Usually, thermoforming machines are placed along with plastic sheet extrusion equipment so that the plastic sheets can be fed into the thermoforming machines using conveyor systems. Heating stations are used to make the plastic sheets soft and malleable. Part-trimming and cropping-toolings can be built into the mold so that further manual cutting and trimming is unnecessary. When the part has been produced it can be finished with paint if necessary. Automated part stackers can be included in the system so that the finished components can be placed in shipping boxes. This process yields high production rates with uniform consistency.